planner

planner is a skill for Claude Code from sflandergan/agentic-coding. It costs 36 tokens per session (1,935 once invoked), scanned A, original, MIT.

A planning workflow that turns an approved specification or clear requirements into a detailed implementation plan. TDD, or test-driven development, means writing tests as part of the implementation process.

In plain words
What is it for?
Use it to investigate a codebase, check whether requirements are clear enough, and create a reviewable plan with implementation and testing steps.
Why use it?
It gives the developer a task-by-task path with the needed context, reducing guesswork before coding begins.

Skill for Claude Code

Written for Claude Code: disable-model-invocation in frontmatter. Also seen: mentions subagents; names the AskUserQuestion tool.

Good fit Use it to investigate a codebase, check whether requirements are clear enough, and create a reviewable plan with implementation and testing steps.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/sflandergan/agentic-coding/planner
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add sflandergan/agentic-coding --skill planner
Clone the repo
git clone --depth 1 https://github.com/sflandergan/agentic-coding

Made for: Claude Code.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for planner

README.md
[![agentmods](https://agentmods.dev/badge/skills/sflandergan/agentic-coding/planner/github.svg)](https://agentmods.dev/skills/sflandergan/agentic-coding/planner)
Your own site
<a href="https://agentmods.dev/skills/sflandergan/agentic-coding/planner"><img src="https://agentmods.dev/badge/skills/sflandergan/agentic-coding/planner/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for planner

Your own site · 80×15
<a href="https://agentmods.dev/skills/sflandergan/agentic-coding/planner"><img src="https://agentmods.dev/badge/skills/sflandergan/agentic-coding/planner.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 36 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,935 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00036 $0.01935
Opus 5.5 $0.00014 $0.00774
Sonnet 5.5 $0.00007 $0.00387
Haiku 4.5 $0.00004 $0.00194

Measured 1mo ago against content hash b2e5328ad1e9, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

planner scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

core/agents/skills/planner/SKILL.md · 234 lines

How it starts

The opening of the file, as written. The whole thing — 234 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Writing Plans

Write comprehensive implementation plans as bite-sized tasks an engineer with zero codebase context can execute: exact files, complete code, testing, and docs for every task. DRY. YAGNI. TDD. Frequent commits.

Load first

Read docs/agents/planner.md and follow it. Load the approved spec first, then every relevant doc listed by docs/agents/planner.md.

If requirements are missing entirely (no spec, no clear requirements), ask the user to provide an approved spec or do a separate brainstorming/design pass. Do not invoke brainstorming automatically.

  • Investigate bounded facts available in the loaded context directly; use the Explore subagent for repository-wide tracing or uncertain boundaries — never guess file paths, module boundaries, or assumptions.

Ordered workflow

  1. Scope check. If the spec covers multiple independent subsystems, suggest breaking it into separate plans — one per subsystem, each producing working, testable software on its own.
  2. UI-design preflight (below).
  3. Resolve uncertainty (below) — plans ship with zero open questions.
  4. Map the file structure. Before defining tasks, decide which files are created or modified and each one's responsibility. Design units with clear boundaries; prefer smaller, focused files; files that change together live together; follow established patterns in existing codebases.
  5. Write the plan following /planning-structure.
  6. Self-review (below), fix inline, and report.

UI-design preflight

Before task decomposition, read the approved spec's ## UI Design section and note the marker. The marker is the spec author's classification — do not change it.

ui-design: required

Verify the following before proceeding:

  1. plans/<feature-dir>/ui-design.md exists as the final handoff.
  2. The handoff contains the following sections: Approval, Scope, Source locations, State inventory, Scenario manifest, Responsive contract, Interaction contract, Accessibility contract, Simulated integrations, Deferred production work, and Regression baseline candidates.
  3. Every referenced tracked source, test, fixture, and adapter exists.
  4. Every stable preview scenario URL listed in the Scenario manifest is reachable.

Read the full file on GitHub · 234 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 1mo ago Changed · +155 lines · +5 tokens per session b2e5328ad1e9
  2. 1mo ago First seen · 79 lines · 31 tokens per session scan A d219f88cfbf7

Subscribe to this mod's changes

planner is a skill published in the GitHub repository sflandergan/agentic-coding (4 stars, last pushed 1mo ago), licensed MIT. It adds 36 tokens to every session and 1,935 once invoked, about $0.0001 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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